Hier mal was ungetestetes:

@echo off
if %2==" " goto ende
FOR /F "usebackq tokens=1,2,3 delims=. " %%a IN ('%date%') DO set datum=%%a-%%b-%%c
FOR /F "usebackq tokens=1,2* delims=*" %%a IN ('%3') DO set text=%%a
find "%text%" %datum%.txt
if "%errorlevel%"=="0" goto keinesmsversenden

:smsversenden

IBSS...

:keinesmsversenden
echo %text%>>%datum%.txt
:ende